Perpendicular Shield Pole Writer with Tapered Main Pole and Tapered Non-Magnetic Top Shaping Layer

ABSTRACT

A PMR writer with a tapered main pole layer and tapered non-magnetic top-shaping layer is disclosed that minimizes trailing shield saturation. A second non-magnetic top shaping layer may be employed to reduce the effective TH size while the bulk of the trailing shield is thicker to allow a larger process window for back end processing. A sloped surface with one end at the ABS and a second end 0.05 to 0.3 microns from the ABS is formed at a 10 to 80 degree angle to the ABS and includes a sloped surface on the upper portion of the main pole layer and on the non-magnetic top shaping layer. An end is formed on the second non-magnetic top shaping layer at the second end of the sloped surface followed by forming a conformal write gap layer and then depositing the trailing shield on the write gap layer and along the ABS.

This is a Divisional application of U.S. patent application Ser. No.11/982,597, filed on Nov. 2, 2007, which is herein incorporated byreference in its entirety, and assigned to a common assignee.

RELATED PATENT APPLICATION

This application is related to U.S. Pat. No. 8,027,125, assigned to acommon assignee, and which is herein incorporated by reference in itsentirety.

FIELD OF THE INVENTION

The invention relates to a PMR writer having a tapered main pole layerand a tapered non-magnetic shaping layer between the main pole layer andan overlying write gap layer to control the effective throat height(TH), and a method for making the same.

BACKGROUND OF THE INVENTION

Shield pole perpendicular magnetic recording (PMR) writers are commonlyused in current PMR (hard disk drive) HDD products. PMR writers havebecome the mainstream technology for disk drive applications beyond 200Gbit/in², replacing longitudinal magnetic recording (LMR) devices. Dueto the continuing reduction of transducer size, high moment softmagnetic thin films with a Bs above 22 kG are required for write headapplications. A PMR head combines the features of a single pole writerand a soft magnetic underlayer to offer a great advantage over LMR inproviding higher write field, better read back signal, and potentiallymuch higher areal density. In particular, a shielded pole head canprovide a large head field gradient at the trailing side due to thepresence of a trailing shield and substantially improve the writeperformance.

Referring to FIG. 1 a, a prior art shield pole PMR writer 1 is depictedfrom a side-track view. There is an essentially flat write gap layer 4which separates a main pole layer 3 and a trailing shield 5 by aconstant (WG) thickness. One end of the main pole layer is formed alongan air bearing surface 6 that is positioned above a magnetic recordingmedium 2. The height of the trailing shield also known as throat height(TH) is the distance from the side of the trailing shield along the ABSto the side opposite the ABS and is typically about 0.1 to 0.3 microns.The PMR writer moves along the ABS in a negative z direction during awrite operation. From a down-track perspective in FIG. 1 b, the mainpole layer 3 is comprised of a write pole 3 a that terminates in a poletip 3 t at the ABS 6-6, and a yoke 3 b that flares outward at an angle θfrom the end of the write pole opposite the ABS. The end of the writepole 3 a lies along the plane 7-7 that is a neck height (NH) distancefrom the ABS. The intersection of the yoke 3 b and write pole 3 a is atthe neck 8. In order to optimize both write field gradient and writefield magnitude, TH (FIG. 1 a) is preferably short. However, in priorart PMR writer structures, a short TH can be very challenging to controlduring the fabrication process. Furthermore, if the TH becomes toosmall, saturation of the trailing shield and degradation of thesignal-to-noise ratio (SNR) may occur. Therefore, an improved PMR writerdesign is desired that is more tolerant of short TH dimensions andenables improved writability while minimizing trailing shield saturationand avoiding loss of process control during fabrication.

A routine search of the prior art revealed the following references. InU.S. Patent Application Publication No. 2005/0219743, a single polevertical write head is described having a trailing shield tapered to thesame angle as the main pole with a constant write gap thickness betweenthe trailing shield and main pole.

In U.S. Patent Application Publication No. 2005/0237665, the main poleis tapered at the leading side to maintain high trailing field gradientsand is shielded on four sides to minimize adjacent track erasure.

U.S. Patent Application Publication No. 2006/0203395 discloses aperpendicular recording head with a tapered magnetic shield to minimizestray fields at the recording surface. The ABS is post-lapped using anion milling process to produce a recess in the shield away from the ABSat a shallow angle.

In U.S. Pat. No. 5,600,519, first and second magnetic layers in amagnetic head are progressively widened (tapered) between a zero throatpoint and a flare point so that the length of the magnetic yoke layersbetween the aforementioned points is saturated nearly simultaneously toprovide a constant write field about a saturation value.

U.S. Pat. No. 5,173,821 discloses a write/read head wherein a steppedpole tip effectively forms a wide gap when the head operates as arecording head and forms a narrow gap when the head functions as a readhead.

SUMMARY OF THE INVENTION

One objective of the present invention is to provide a shield pole PMRwriter with a configuration that reduces the amount of trailing shieldsaturation.

A second objective of the present invention is to provide a process forfabricating a shield pole PMR writer according to the first objectivethat includes a means for controlling the effective TH of a trailingshield.

According to the present invention, these objectives are achieved by atapered main pole layer that has at least one non-magnetic top shapinglayer to separate the main pole layer from the write gap layer. In oneembodiment, from a cross-track view, the main pole layer has a lowerrectangular portion disposed on a substrate and a tapered upper portionadjoining the lower portion in which the taper begins at the ABS andextends away from the ABS and the substrate at an angle of about 10 to80 degrees for a certain distance to form a sloped section of the topsurface. The top surface of the upper portion also has a flat sectionthat is parallel to the plane of the bottom portion and extends from theend of the sloped section opposite the ABS to the back end of the mainpole layer in a direction perpendicular to the ABS. Above the taperedmain pole layer is a tapered non-magnetic top shaping layer having abottom surface that coincides with the flat section of top surface inthe upper portion of the main pole layer. The tapered non-magneticshaping layer has a sloped surface that extends from the end of thetapered section of main pole layer and is coplanar with the taperedsection of main pole layer. Thus, the plane formed by the sloped surfaceof the top shaping layer and sloped surface of the upper portion of mainpole layer extends from the ABS at an angle between 10 and 80 degrees ina direction away from the substrate, and terminates at an end which is athroat height (TH) distance from the ABS. The top shaping layer has atop surface that is parallel to the top surface of the flat section ofthe main pole layer. A conformal write gap layer having a constantthickness is formed on the top shaping layer and on the sloped portionof the upper section of main pole layer. In other words, the write gaplayer has a sloped section from the ABS to a TH distance from the ABSand a section parallel to the plane of the substrate that covers the topsurface of the top shaping layer. There is a trailing shield formed onthe sloped section of the write gap layer that has a TH thickness and alength along the ABS which is greater than the combined thicknesses ofthe top shaping layer and write gap layer.

The present invention takes advantage of a design where tapering asection of the main pole layer adjacent to the ABS serves to concentratethe magnetic flux and generate a larger write field. The top shapinglayer is tapered to allow the effective TH of the trailing shield toremain small and to be in good process control. In a second embodiment,the distance (and magnetic reluctance) between the main pole layer andtrailing shield is increased to reduce the magnetic flux leakage fromthe main pole layer to the trailing shield and thereby minimizessaturation of the trailing shield.

The second embodiment has a tapered main pole layer formed on asubstrate as in the first embodiment and there is a first non-magnetictop shaping layer formed on the flat top surface of the main pole layer.In addition, there is a second top shaping layer with a rectangularshape that is formed on the top flat surface of the first top shapinglayer. A conformal write gap layer with an essentially constantthickness is formed on the sloped sections of the main pole layer andfirst top shaping layer, on the top surface of the second top shapinglayer, and along a side of the second top shaping layer that faces theABS. The trailing shield is formed on the write gap layer and along theABS, and extends over a portion of the write gap layer disposed on thetop surface of the second top shaping layer. The trailing shield has alength along the ABS that is greater than the combined thicknesses ofthe first top shaping layer, second top shaping layer, and write gaplayer. The effective throat height distance is defined as the thicknessof the trailing shield between the ABS and the portion of the write gaplayer along the side of the second top shaping layer that faces the ABS.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a cross-track view of a prior art shield pole PMR writerwith a flat write gap layer that has a constant thickness on the mainpole layer and FIG. 1 b is a down-track view of a prior art PMR writer.

FIG. 2 is cross-track view of a shield pole PMR writer previouslydesigned by the inventors that has a tapered main pole layer and taperedwrite gap layer.

FIG. 3 is a cross-track view of a shield pole PMR writer previouslydesigned by the inventors that has a tapered main pole layer and arectangular top shaping layer on the main pole layer.

FIG. 4 a is a cross-track view of a PMR writer having a tapered topshaping layer on a tapered main pole layer according to one embodimentof the present invention.

FIG. 4 b is a cross-track view of a PMR writer having a second topshaping layer formed on a tapered first top shaping layer on a taperedmain pole layer according to a second embodiment of the presentinvention.

FIGS. 5 a-5 d are cross-sectional views that depict a sequence of stepsfor forming a PMR writer according to the first embodiment of thepresent invention.

FIGS. 6 a-6 c are cross-sectional views that depict a sequence of stepsfor forming a PMR writer according to a second embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is shield pole PMR writer having a tapered mainpole layer and a tapered top shaping layer for minimizing trailingshield saturation and a method for making the same. The exemplaryembodiment shows only a portion of the main pole layer proximate to anABS. The present invention anticipates that the PMR writer may be partof a merged read/write head. Furthermore, the main pole layer may becomprised of a single piece or have a stitched pole configuration. Froma down-track perspective, the main pole layer may have various shapessuch as the conventional shape shown in FIG. 1 b or one with curvedsides in the yoke as appreciated by those skilled in the art.

Referring to FIG. 2, the inventors have previously designed a PMR writer10 with a tapered main pole layer 11 and a tapered write gap layer thatis conformally laid on an upper portion 11 b of the main pole layer. Thewrite gap layer is comprised of a sloped section 12 a adjacent to theABS 14-14 and a flat section 12 b formed parallel to the bottom surface11 d of the main pole layer, and has a constant thickness e also knownas the WG thickness. A bottom portion 11 a of the main pole layer 11 isdisposed on a substrate (not shown) which may be an insulating layer,for example, and terminates at a pole tip 11 t at the ABS 14-14. Thereis a trailing shield 13 having a thickness TH (perpendicular to the ABS)on the sloped section 12 a and over a portion of the flat section 12 bof the write gap layer. The sloped section 12 a is tapered at an angle αof about 10 to 80 degrees with respect to the ABS 14-14 and extends fromthe ABS in a direction away from the bottom surface 11 d. One end of thesloped section 12 a terminates at a distance s of about 0.05 to 0.30microns from the ABS. The trailing shield 13 has a length m along theABS that is greater than the combined thicknesses of the write gap layer12 b and upper portion 11 b of the main pole layer. By forming a taperedmain pole layer 11, magnetic flux will be concentrated at the ABS and alarger write field can be expected.

Referring to FIG. 3, another PMR writer design previously designed butnot published by the inventors is shown and combines the features of thestructure in FIG. 2 with a non-magnetic top shaping layer 15 having athickness f formed between the upper portion 11 b of the tapered mainpole layer and a section 12 c of the write gap layer to further improvewritability. In this example, the top shaping layer 15 is essentiallyrectangular in shape and is formed only on a flat surface 11 c of themain pole layer that is parallel to the bottom surface 11 d. The writegap layer is comprised of a section 12 a formed on the tapered surface11 s of the main pole layer 11, a section 12 b formed on an end of thetop shaping layer 15 that faces the ABS, and a section 12 c formed onthe upper surface of the top shaping layer which is parallel to theplane of the substrate and bottom surface 11 d. The effective TH of thetrailing edge 13 e is shown as the distance s and is defined as thethickness of the trailing shield 13 between write gap section 12 b andthe ABS 14-14. Thus, the effective TH thickness of the trailing shieldcan remain small as desired in advanced PMR writers while the thicknessk of the trailing shield above the write gap layer 12 c can be thickerthan s and thereby allows a wider process window for processing stepsincluding back end steps. However, when the effective TH or “s”dimension becomes too thin, this design may have issues with saturationof the trailing shield 13 due to the trailing shield's close proximityto the main pole layer 11. As a result, additional modification of thetapered main pole layer design shown in FIGS. 2 and 3 is desirable.

The inventors have discovered that the performance of a shield pole PMRwriter may be further improved by addition of a tapered top shapinglayer to the designs originally proposed in FIGS. 2 and 3.

Referring to FIG. 4 a, a first embodiment of the present invention isdepicted as a PMR writer 20 that represents a modification of the PMRwriter structure in FIG. 2. A main pole layer 21 with a bottom surface21 d formed on a substrate (not shown) is comprised of a lowerrectangular portion 21 a having a pole tip 21 t at an ABS 25-25, and atapered upper portion 21 b which adjoins the lower rectangular portionand has a flat upper surface 21 c that is parallel to the bottom surface21 d. The tapered upper portion 21 b has a sloped surface 21 s thatbegins at the ABS and extends away from the lower rectangular portion 21a at an angle β of about 10 to 80 degrees with respect to the ABS 25-25.In other words, the sloped surface 21 s has one end at the ABS and asecond end at a position where the sloped surface 21 s intersects theflat upper surface 21 c.

There is a non-magnetic tapered top shaping layer 22 made of Al₂O₃, Ru,or the like having a thickness from 0 to 0.3 microns that is formed onthe flat upper surface 21 c of the tapered upper portion 21 b of themain pole layer 21. It should be understood that the main pole layer 21and tapered top shaping layer 22 extend in the “x” directionperpendicular to the ABS for up to 5 to 20 microns before terminating atthe back end (not shown) of the main pole layer. The tapered top shapinglayer 22 has a sloped surface 22 s which is an extension of the slopedsurface 21 s. The sloped surface 22 s begins at the end of the slopedsurface 21 s opposite the ABS and continues to a second end that is adistance of 0.1 to 0.3 microns from the ABS 25-25. Thus, the slopedsurface 21 s and sloped surface 22 s form a plane that faces the ABS atan angle between 10 and 80 degrees. The point where the sloped surface22 s adjoins the sloped surface 21 s is recessed about 0.05 to 0.20microns from the ABS 25-25 and this recess represents the effectivethroat height distance. The tapered top shaping layer 22 also has a flatupper surface 22 c that is parallel to the flat upper surface 21 c ofthe main pole layer 21.

Another feature of the first embodiment is a conformal write gap layercomprised of a sloped section 23 a with a surface 23 s formed on thesloped surfaces 21 s, 22 s, and a section 23 d on the flat upper surface22 c. The sloped section 23 a has an end along the ABS and adjoinssection 23 d at a distance of 0.1 to 0.3 microns from the ABS 25-25. Thewrite gap layer may be a non-magnetic material such as Al₂O₃ or the likeand has a thickness from 0.02 to 0.08 microns. Above the sloped section23 a of the write gap layer is a trailing shield 24 that may becomprised of a high Bs magnetic material such as Fe, Co, Ni, FeNi, CoFe,or alloys thereof. The main pole layer 21 may also be comprised of thesame high Bs magnetic material. The trailing shield has a first sidealong the ABS 25-25 with a length n and a second side opposite andparallel to the ABS with a length w that is less than n. The distancebetween the first and second sides is the TH distance. The second sideopposite the ABS has one end at the intersection of the sloped section23 a and section 23 d of the write gap layer. There is a sloped side ofthe trailing shield 24 disposed on the sloped surface 23 s of the writegap layer which is formed at an angle β with respect to the ABS. Afourth side 24 a of the trailing shield opposite the sloped surface 23 sis preferably aligned perpendicular to the ABS 25-25.

The PMR writer 20 has an advantage over the structure shown in FIG. 2 inthat the flat upper surface 21 c of the main pole layer 21 is a greaterdistance from the trailing shield 24 than the upper surface 11 c is fromtrailing shield 14. As a result, there is less magnetic flux leakagefrom the main pole layer 21 to the trailing shield 24 in PMR writer 20which means saturation of the trailing shield 24 will be reduced.

Referring to FIG. 4 b, a second embodiment of the present invention isdepicted as a PMR writer 30 that represents a modification of the PMRwriter structure in FIG. 3. In particular, a tapered top shaping layer22 is inserted between a rectangular top shaping layer 26 and the topsurface 21 c of the main pole layer 21. The main pole layer 21 has thesame configuration as described previously with respect to FIG. 4 a.Furthermore, the plane formed by sloped surface 21 s and sloped surface22 s is formed at an angle β with respect to the ABS similar to FIG. 4a, but terminates at an end which is less than the length of side 24 afrom the ABS 25-25. As in the first embodiment, the sloped surface 22 smay terminate at an end that intersects top surface 22 c which is fromabout 0.5 to 0.30 microns from the ABS.

Above the flat upper surface 22 c of the tapered first non-magnetic topshaping layer is a second non-magnetic top shaping layer 26 that has athickness from 0 to 0.5 microns. The second non-magnetic top shapinglayer 26 may be comprised of the same material as in the tapered firstnon-magnetic top shaping layer 22. The second non-magnetic top shapinglayer 26 has a bottom surface that is coincident with top surface 22 cand has a flat top surface 26 c which terminates at a first end which isparallel to the ABS and is recessed the same distance from the ABS 25-25as the intersection of sloped surface 22 s and top surface 22 c. Asecond end of the second non-magnetic top shaping layer 26 is at theback end (not shown) of the main pole layer 21.

There is a conformal write gap layer having a thickness from 0.02 to0.08 comprised of a sloped section 23 a on the sloped surfaces 21 s, 22s, a section 23 b formed on the first end of the second non-magnetic topshaping layer 26 that faces the ABS 25-25, and a section 23 d whichcovers the flat upper surface 26 c. The sloped section 23 a has an endalong the ABS and a second end that adjoins one end of section 23 b.Note that the section 23 b has a surface 23 p facing the ABS which is adistance v from the ABS 25-25. The distance v represents the effectiveTH distance and is preferably about 0.05 to 0.3 microns.

A trailing shield 24 has a first side that is coincident with thesurface 23 s of the sloped section 23 a, and a second side 24 b formedalong the ABS 25-25. The trailing shield 24 has a third side 24 aopposite the surface 23 s and preferably aligned perpendicular to theABS. There is a fourth side 24 c of the trailing shield that connects anend of the side 24 a opposite the ABS to the write gap layer section 23d. Fourth side 24 c is parallel to the ABS and has a length g which isless than the length of side 24 b. Fourth side 24 c intersects write gaplayer section 23 d at a distance r of about 0.1 to 0.5 microns from theABS 25-25. A fifth side 24 d of the trailing shield extends from an endof fourth side 24 c at section 23 d and terminates at surface 23 p ofsection 23 b. A sixth side of the trailing shield 24 is coincident withsurface 23 p of section 23 b.

The PMR writer 30 has an advantage over the structure shown in FIG. 3 inthat the main pole layer 21 is a greater distance from the trailingshield 24 than the main pole layer 11 is from trailing shield 14. As aresult, there is less magnetic flux leakage from the main pole layer 21to the trailing shield 24 in PMR writer 30 which means saturation of thetrailing shield 24 will be reduced. Similar to the structure in FIG. 3,the rectangular top shaping layer is advantageously used to control theeffective TH distance. Therefore, the effective TH distance or “v” canbe small and be in good process control while the thickness of thetrailing shield or “r” may be thick and thereby offers a better processwindow for back end fabrication schemes.

Referring to FIGS. 5 a-5 d, a sequence of steps is depicted forfabricating the PMR writer 20 of the first embodiment. In FIG. 5 a, themain pole layer 21 is deposited on a substrate (not shown) that may bean insulation layer in a merged read/write head as appreciated by thoseskilled in the art. Note that the bottom surface 21 d is coincident withthe top surface of the substrate. The main pole layer 21 may be formedby an electroplating or sputter deposition method. In one embodiment, amold or opening having the shape of the intended main pole layer isformed within a second insulation layer (not shown) disposed on thesubstrate. The main pole layer is then deposited to fill the opening andis subsequently planarized such that the top surface has a uniformthickness and is coplanar with the top surface of the second insulationlayer. Optionally, the main pole layer material may be electroplated orsputter deposited on a substrate and then patterned in the shape of amain pole layer by a well known photoresist patterning and etchingsequence. Thereafter, the photoresist is removed and the secondinsulation layer is deposited on the main pole layer and on exposedportions of the substrate. Then a chemical mechanical polish (CMP) stepmay be performed to planarize the second insulation layer to becomecoplanar with the main pole layer 21. The ABS plane 25-25 is not shownbecause it is not formed until later in the fabrication sequence afterthe entire stack of layers in the PMR writer 20 is built.

The next step is to deposit the non-magnetic top shaping layer 22 havinga thickness from 0 to about 0.3 microns on the main pole layer 21 by asputter deposition process, for example. All sputter deposition stepsduring the fabrication of PMR writer 20 may be performed in a singlemainframe such as an Anelva C-7100 sputter deposition system whichincludes ultra high vacuum DC magnetron sputter chambers with multipletargets and at least one oxidation chamber. Typically, the sputterdeposition process involves an argon sputter gas and a base pressurebetween 5×10⁻⁸ and 5×10⁻⁹ torr. A lower pressure enables more uniformfilms to be deposited.

Referring to FIG. 5 b, a photoresist layer 50 is coated on thenon-magnetic top shaping layer 22 and is patterned to cover a regionthat will become the top surface 22 c in the PMR writer 20. Although thephotoresist layer 50 is shown recessed the same distance a from a plane28-28 as the intended end of sloped surface 22 s, the photoresist layer50 may optionally be recessed a greater distance than a. Thereafter, anion beam etch (IBE) step is performed that is directed an angle towardthe photoresist layer 50 and non-magnetic top shaping layer 22. The etchprocess continues until the sloped surface 22 s and sloped surface 21 sare generated to produce a tapered top shaping layer 22 and a taperedmain pole layer 21, respectively. The sloped surfaces 21 s, 22 s form aplane that is oriented away from the bottom surface 21 d and at an angleβ of about 10 to 80 degrees with respect to a plane 28-28 that isoriented perpendicular to the bottom surface. The distance a between thepatterned photoresist layer 50 and the plane 28-28 should be greaterthan the intended TH distance since a lapping process later in thefabrication sequence will remove a portion of the main pole layer 21adjacent to plane 28-28 and thereby form an ABS 25-25 as depicted inFIG. 4 a.

Referring to FIG. 5 c, the photoresist layer 50 is stripped by aconventional method such as oxygen ashing and then the write gap layercomprised of a sloped section 23 a and section 23 d is deposited by aphysical vapor deposition (PVD) method or chemical vapor deposition(CVD) process, for example. The write gap layer may be made of Al₂O₃ oranother non-magnetic material such as Ru and is deposited by a processthat yields a conformal write gap layer having an essentially constantthickness in sections 23 a, 23 d. As a result, section 23 a is formed atan angle β with respect to the plane 28-28 that is perpendicular to thebottom surface 21 d and has an end adjoining section 23 d which is adistance a from the plane 28-28.

Referring to FIG. 5 d, a photoresist layer 51 is coated on the write gaplayer and patterned to cover section 23 d of the write gap layer.Section 23 a is uncovered by the photoresist patterning step. Next, theshield layer 24 is deposited on section 23 a by a electroplating orsputter deposition process. Typically, a seed layer (not shown) isdeposited on section 23 a before the shield layer 24 is formed in orderto assist the electroplating process. A CMP step may be employed toplanarize the shield layer 24 and form the end 24 a of the trailingshield shown in FIG. 4 a. The photoresist layer 51 is then removed by aconventional method. Finally, a lapping process is performed to form theABS 25-25 depicted in FIG. 4 a. The ABS is formed between the plane28-28 and the non-magnetic top shaping layer 22 and is substantiallyperpendicular to the substrate. It should be understood that a pluralityof PMR writers 20 may be formed simultaneously in rows and columns on asubstrate and later separated from each other by a process that dicesthe wafer into chips.

In FIGS. 6 a-6 c, a sequence of steps is depicted for fabricating thePMR writer 30 of the second embodiment. Referring to FIG. 6 a which is across-track view of the partially formed PMR writer 30, a main polelayer 21 and a first top shaping layer 22 are sequentially deposited ona substrate as described with respect to FIG. 5 a in the firstembodiment. A second non-magnetic top shaping layer 26 is deposited onthe first top shaping layer 22 and may be a single non-magnetic layer ora composite having a plurality of non-magnetic layers. Next, aphotoresist layer 52 is patterned on the second non-magnetic top shapinglayer 26 to generate an opening 29 having a width b between a plane28-28 and the photoresist layer 52. An etching step that may be areactive ion etch (RIE) process is used to transfer the opening 29through the second non-magnetic top shaping layer 26 and thereby form anend 26 e parallel to the plane 28-28. The opening 29 in the secondnon-magnetic top shaping layer 26 preferably has a width b. Thepatterned photoresist layer 52 defines the top surface 26 c (FIG. 6 b)of the second non-magnetic top shaping layer 26 in the PMR writer 30 andis removed after the RIE step is complete. Note that the location of theABS will be determined by a lapping process in a later step and the ABS25-25 (FIG. 4 b) will be positioned between the plane 28-28 and thenon-magnetic top shaping layer 26.

Referring to FIG. 6 b, a second etch step that may be an IBE process isperformed at an oblique angle with respect to the plane 28-28 to form atapered upper portion 21 b of the main pole layer 21 and a tapered firstnon-magnetic top shaping layer 22. The second etch is preferablyperformed after a photoresist layer (not shown) is coated on thenon-magnetic top shaping layer 26 and then patterned as understood bythose skilled in the art. The taper angle is 10 to 80 degrees similar toangle β in the first embodiment. As a result, a sloped surface 21 s isformed on the upper portion 21 b of the main pole layer and a slopedsurface 22 s is formed on the first non-magnetic top shaping layer 22below opening 29. The patterned photoresist layer used for the IBEprocess may then be removed. Thereafter, the write gap layer comprisedof sloped section 23 a, section 23 b, and section 23 d is conformallylaid down on the sloped surfaces 21 s, 22 s, and on the top surface 26 cof the second non-magnetic top shaping layer 26 with a thickness that isessentially constant in sections 23 a, 23 b, and 23 d. Sloped section 23a is formed on the sloped surfaces 21 s, 22 s while section 23 b adjoinsthe end 26 e, and section 23 d is disposed on top surface 26 c. Thewrite gap layer may be made of Al₂O₃ or Ru as mentioned previously andmay be deposited by a PVD or CVD method, for example. The opening 29 nowhas a width v₁ that is less than the width b (FIG. 6 a) because of theadditional write gap layer. In particular, the section 23 b facing theplane 28-28 reduces the width of the opening 29. The width v₁ is greaterthan the effective TH distance v that separates ABS 25-25 and write gaplayer section 23 b in the completed PMR writer 30.

Referring to FIG. 6 c, a photoresist layer 53 is coated and patterned onthe write gap layer to form an opening 31 above opening 29. Opening 31has a width r₁ (greater than r in FIG. 4 b) and uncovers a portion ofthe write gap layer section 23 d adjacent to section 23 b. The openings29 and 31 define the shape of the trailing shield which is preferablydeposited by an electroplating process in the openings in the followingstep. Next, the photoresist layer 53 is removed and an insulation layer(not shown) may be deposited on the trailing shield and on section 23 dof the write gap layer. Thereafter, a CMP process may be used toplanarize the trailing shield 24 to form the end 24 a (FIG. 4 b) whichis parallel to bottom surface 21 d in the main pole layer 21 and iscoplanar with the adjacent insulation layer. Subsequently, a lappingprocess is employed to remove a portion of the trailing shield 24,sloped section 23 a, and the bottom portion 21 a of the main pole layeradjacent to plane 28-28 and thereby form the ABS 25-25 and the PMRwriter 30 shown in FIG. 4 b.

Both embodiments provide an advantage over existing PMR writers in thatsaturation of the trailing shield is minimized by the designs describedherein that include a tapered main pole layer and a tapered top shapinglayer. Furthermore, the tapered main pole layer and tapered top shapinglayer enable the effective TH to be small while the bulk of the trailingshield is larger and thereby allows a larger process window during backend fabrication steps such as the CMP step that planarizes the trailingshield and adjacent insulation layer.

While this invention has been particularly shown and described withreference to, the preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade without departing from the spirit and scope of this invention.

1. A perpendicular magnetic recording (PMR) writer, comprising: (a) atapered main pole layer comprised of a lower portion formed on asubstrate and having a pole tip at an air bearing surface (ABS), and anupper portion having a sloped surface with one end at the ABS and anopposite end formed a certain distance from the ABS such that saidopposite end is a greater distance from the substrate than the firstend, said lower portion has a upper surface formed parallel to thesubstrate and said upper portion has an upper surface connected to theopposite end of the sloped surface and aligned parallel to thesubstrate; (b) a tapered first non-magnetic top shaping layer formed onthe upper surface of the upper portion of the main pole layer, saidnon-magnetic top shaping layer has a sloped surface with a first endconnected to the opposite end of the sloped surface of the main polelayer and a second end that is a greater distance from the substratethan the first end, and said non-magnetic top shaping layer has an uppersurface that is parallel to the substrate and is connected to saidsecond end at a first distance from the ABS; (c) a second non-magnetictop shaping layer formed on the upper surface of the tapered firstnon-magnetic top shaping layer, said second non-magnetic top shapinglayer has an end formed parallel to the ABS and separated by a firstdistance from the ABS, and has an upper surface connected to said endand formed parallel to the substrate; (d) a conformal write gap layerhaving a first section with a top surface formed on the sloped surfaceof the upper portion of the main pole layer and on the sloped surface ofthe non-magnetic top shaping layer, a second section having a topsurface facing the ABS on said end of the second non-magnetic topshaping layer, and a third section on the upper surface of the secondnon-magnetic shaping layer that extends to a second distance from theABS; and (e) a trailing shield formed on the first section and over aportion of the third section of the conformal write gap layer, saidtrailing shield has a first side along the ABS, a second side oppositethe first side that is a second distance from the ABS, a third sidecoincident with the top surface of said first section, a fourth sidecoincident with the top surface of said second section, and a sideopposite the third side that connects the first and second sides.
 2. ThePMR writer of claim 1 wherein the sloped surface of the upper portion ofthe main pole layer and the sloped surface of the non-magnetic topshaping layer form a plane aligned at an angle of about 10 degrees to 80degrees with respect to the ABS.
 3. The PMR writer of claim 2 whereinthe plane extends a distance of about 0.05 to 0.30 microns from the ABS.4. The PMR writer of claim 1 wherein the tapered first non-magnetic topshaping layer has a thickness from 0 to about 0.3 microns and iscomprised of Al₂O₃ or Ru.
 5. The PMR writer of claim 1 wherein thesecond non-magnetic top shaping layer has a thickness from 0 to about0.5 microns and is made of the same material as in the tapered firstnon-magnetic top shaping layer.
 6. The PMR writer of claim 1 wherein theconformal write gap layer has a thickness of about 0.02 to 0.08 micronsand is made of a non-magnetic material.